It has been a freezing journey full of icy hazards around the world’s most remote continent, but Polish businessman Mariusz Koper and his crew have achieved their goal of an historic circumnavigation of Antarctica.

The fierce weather hasn’t been the only foe, with crew members overcoming significant personal challenges to join the voyage.

The crew of the 72-foot yacht Katharsis II have spent the last 103 days in some of the world’s most difficult seas, as part of a challenge to loop Antarctica entirely south of the 60th parallel.

Katharsis II and its team of eight, all Polish, are now into the home stretch to the finish line in Hobart, after leaving from Cape Town on December 23.

They finished the circumnavigation in 72 days and closed the loop at 62 degrees south.

But it’s been far from smooth sailing.

The Oyster class yacht was struck by an “exceedingly” big wave during storm conditions last week.

The rogue wave knocked the mainsail in the opposite direction of the boom, with captain Koper reporting in his skipper’s log that the force fractured the boom.

“In a swift swerve, the boom crashed into rigging on the yacht’s other side,” he said.

“Fortunately, the rigging took the impact well, saving the mainmast.

“But our carbon fibre boom — robust but not impact-resistant — is now fractured and will have to be replaced.”

The vessel has since been using its foresails only, and means its speed has dropped by a third or more when travelling into the wind.

The yacht is no stranger to difficult conditions, and in 2014 it successfully completed the Sydney to Hobart race, finishing 16th in its class and again at the 2017 race, this time taking out 65th in Line Honours ranking.

The skipper reports the boom incident “has proven that Katharsis II is a seaworthy yacht capable of delivering us to the planned destination, even without its mainsail”.

The expedition, a total distance of around 17,000 nautical miles (13,500 kilometres), has been dedicated to “the prevention of breast cancer in women”.

Much more than a sailing achievement

When crew member Hanna Leniec was diagnosed with breast cancer in November 2016 she thought her dream of joining the voyage could be over.

After gruelling treatment, she was determined to be aboard Katharsis II when it left Cape Town.

The crew then dedicated the voyage to fighting the disease.

On New Year’s Day, she wrote that “it has been a rough year. A year of struggle with grave illness”.

“A year that saw me mature in a way and better understand myself. A year that has demonstrated that I may always count on my nearest and dearest, my friends and my sailing family — Katharsis II crew.

“A year during which I learnt a lot about cancer, about what it really means, how it changes your everyday life, but also that it is curable and does not put an end to a normal life.

“We tend to think that if we don’t talk about something and pretend it doesn’t exist, this will never happen to us. But this is not how it works.

“The sooner you learn about cancer, the bigger are the odds of beating it.”

After the Katharsis II completed the Antarctic loop, she recorded feelings of “joy and reflection”.

“I couldn’t help but glance back at the disease I had suffered,” she wrote.

“A fleeting thought: Antarctica could have passed me by.

“I, myself, could have been no more — had it not been for pre-expedition medical tests and the early cancer diagnosis.”

Leniec urged other women to get themselves checked.

“I was given this chance because I went to get a check up. I would like to see more females making the most of this chance they are given,” she wrote.

“To live on and fulfil their dreams.”

Also on board is Polish scientist Piotr Kuklinski who has been researching the Antarctic climate along the way.

A professor at the Institute of Oceanology of the Polish Academy of Sciences, he has been contributing to research on changes to oceans as well as contamination caused by plastics, and whether plastics have reached the waters around Antarctica.

Last year Queensland sailor Lisa Blair became the first women to sail around Antarctica solo, spending 184 days at sea.

Before setting off on their voyage, the crew of Katharsis caught up with Blair in Cape Town, where she was repairing her yacht prior to her record-breaking journey.

In May 2008, Russian voyager Fedor Konyukhov became the first person to complete a solo circumnavigation of Antarctica in a sailboat.

The Russian attempt took 102 days in total, beginning and ending in Australia, which is the current record.

His route fell between the 45th and 60th parallels south.

Until now, no yacht has looped the icy continent entirely south of the 60th parallel.

The Katharsis II and triumphant crew are expected in Hobart early on Thursday.